# API Tokens API Tokens are strings that allow to authenticate API calls. ### Format They are issued and used in the form of UUID represented in [canonical format](https://en.wikipedia.org/wiki/Universally_unique_identifier#Format), for example `123e4567-e89b-12d3-a456-426614174000`. ### Usage API Tokens should be used with bearer authentication. They need to be passed with the request as `authorization` Header with type `Bearer`. For example: ```bash curl --request GET \ --url 'https://testapi.aviowiki.com/airports/search?query=London' \ --header 'Authorization: Bearer 123e4567-e89b-12d3-a456-426614174000' ``` ### API Token types There are two types of API Tokens, `API` or `API_FREE`. `API_FREE` tokens allow access only to [Free Endpoints](/free-endpoints/limitations.md), without rate limitations. \ Such Tokens can be issued autonomously by every user as they do not require any contractual agreement in place, other than accepting the regular [Terms and Conditions](https://www.aviowiki.com/terms/). `API` tokens allow access to all endpoints.\ At the moment, these Tokens can only be issued by an aviowiki administrator, and an agreement need to be signed between the User and aviowiki. Please [get in touch](mailto:hello@aviowiki.com) if you require an `API` token. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.aviowiki.com/authentication/api-tokens.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.